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https://www.readbyqxmd.com/read/28429167/corynebacterium-defluvii-sp-nov-isolated-from-sewage
#1
Qiu-Li Yu, Zheng-Fei Yan, Xin He, Feng-Hua Tian, Chuan-Wen Jia, Chang-Tian Li
A Gram-positive, aerobic, non-motile, rod-shapeds, cata-lase-positive, and oxidase-negative strain, designated Y49(T), was isolated from sewage collected from Jilin Agricultural University, China. It grew at 20-40°C (optimum at 30°C), at pH 6.0-8.0 (optimum at 7.0) and at 0-1.0% sodium chloride (optimum at 0%). The major isoprenoid quinone was menaquinone-8 (MK-8) and the polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, four unidentified lipids, and two unidentified aminolipids...
April 20, 2017: Journal of Microbiology / the Microbiological Society of Korea
https://www.readbyqxmd.com/read/28417190/larkinella-harenae-sp-nov-isolated-from-korean-beach-soil
#2
Su-Jin Park, Jae-Jin Lee, Seung-Yeol Lee, Dae Sung Lee, Myung Kyum Kim, Leonid N Ten, Hee-Young Jung
A Gram-negative, short rod-shaped, gliding motile, and pale pink-pigmented bacterial strain, designated 15J9-9(T), was isolated from the soil of Iho Tewoo Beach, Jeju Island, Korea, and characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 15J9-9(T) belonged to the family Cytophagaceae and was related to Larkinella bovis M2T2B15(T) (96.5% similarity), Larkinella arboricola Z0532(T) (95.3% similarity), and Larkinella insperata LMG 22510(T) (95...
April 17, 2017: Current Microbiology
https://www.readbyqxmd.com/read/28405861/pk-a-of-ubiquinone-menaquinone-phylloquinone-plastoquinone-and-rhodoquinone-in-aqueous-solution
#3
Ryo Hasegawa, Keisuke Saito, Tomohiro Takaoka, Hiroshi Ishikita
Quinones can accept two electrons and two protons, and are involved in electron transfer and proton transfer reactions in photosynthetic reaction centers. To date, the pK a of these quinones in aqueous solution have not been reported. We calculated the pK a of the initial protonation (Q(·-) to QH(·)) and the second protonation (QH(-) to QH2) of 1,4-quinones using a quantum chemical approach. The calculated energy differences of the protonation reactions Q(·-) to QH(·) and QH(-) to QH2 in the aqueous phase for nine 1,4-quinones were highly correlated with the experimentally measured pK a(Q(·-)/QH(·)) and pK a(QH(-)/QH2), respectively...
April 12, 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28403946/vitamin-k-and-osteoporosis-myth-or-reality
#4
REVIEW
Andrea Palermo, Dario Tuccinardi, Luca D'Onofrio, Mikiko Watanabe, Daria Maggi, Anna Rita Maurizi, Valentina Greto, Raffaella Buzzetti, Nicola Napoli, Paolo Pozzilli, Silvia Manfrini
Vitamin K is a liposoluble vitamin. The predominant dietary form, phylloquinone or vitamin K1, is found in plants and green vegetables; whereas menaquinone, or vitamin K2, is endogenously synthesized by intestinal bacteria and includes several subtypes that differ in side chain length. Aside from its established role in blood clotting, several studies now support a critical function of vitamin K in improving bone health. Vitamin K is in fact required for osteocalcin carboxylation that in turn regulates bone mineral accretion; it seems to promote the transition of osteoblasts to osteocytes and also limits the process of osteoclastogenesis...
May 2017: Metabolism: Clinical and Experimental
https://www.readbyqxmd.com/read/28396391/enhanced-respiration-prevents-drug-tolerance-and-drug-resistance-in-mycobacterium-tuberculosis
#5
Catherine Vilchèze, Travis Hartman, Brian Weinrick, Paras Jain, Torin R Weisbrod, Lawrence W Leung, Joel S Freundlich, William R Jacobs
Persistence, manifested as drug tolerance, represents a significant obstacle to global tuberculosis control. The bactericidal drugs isoniazid and rifampicin kill greater than 99% of exponentially growing Mycobacterium tuberculosis (Mtb) cells, but the remaining cells are persisters, cells with decreased metabolic rate, refractory to killing by these drugs, and able to generate drug-resistant mutants. We discovered that the combination of cysteine or other small thiols with either isoniazid or rifampicin prevents the formation of drug-tolerant and drug-resistant cells in Mtb cultures...
April 10, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28326075/advantages-of-the-silkworm-as-an-animal-model-for-developing-novel-antimicrobial-agents
#6
REVIEW
Suresh Panthee, Atmika Paudel, Hiroshi Hamamoto, Kazuhisa Sekimizu
The demand for novel antibiotics to combat the global spread of multi drug-resistant pathogens continues to grow. Pathogenic bacteria and fungi that cause fatal human infections can also kill silkworms and the infected silkworms can be cured by the same antibiotics used to treat infections in the clinic. As an invertebrate model, silkworm model is characterized by its convenience, low cost, no ethical issues. The presence of conserved immune response and similar pharmacokinetics compared to mammals make silkworm infection model suitable to examine the therapeutic effectiveness of antimicrobial agents...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28325762/a-genetic-screen-reveals-that-synthesis-of-1-4-dihydroxy-2-naphthoate-dhna-but-not-full-length-menaquinone-is-required-for-listeria-monocytogenes-cytosolic-survival
#7
Grischa Y Chen, Courtney E McDougal, Marc A D'Antonio, Jonathan L Portman, John-Demian Sauer
Through unknown mechanisms, the host cytosol restricts bacterial colonization; therefore, only professional cytosolic pathogens are adapted to colonize this host environment. Listeria monocytogenes is a Gram-positive intracellular pathogen that is highly adapted to colonize the cytosol of both phagocytic and nonphagocytic cells. To identify L. monocytogenes determinants of cytosolic survival, we designed and executed a novel screen to isolate L. monocytogenes mutants with cytosolic survival defects. Multiple mutants identified in the screen were defective for synthesis of menaquinone (MK), an essential molecule in the electron transport chain...
March 21, 2017: MBio
https://www.readbyqxmd.com/read/28304162/rational-design-synthesis-and-biological-evaluation-of-heterocyclic-quinolones-targeting-the-respiratory-chain-of-mycobacterium-tuberculosis
#8
Weiqian David Hong, Peter D Gibbons, Suet C Leung, Richard Amewu, Paul A Stocks, Andrew Valentine Stachulski, Pedro C Horta, Maria Lurdes Santos Cristiano, Alison E Shone, Darren Moss, Alison Ardrey, Raman Sharma, Ashley J Warman, Paul T P Bedingfield, Nicholas E Fisher, Ghaith Aljayyoussi, Sally Mead, Maxine Caws, Neil G Berry, Stephen A Ward, Giancarlo A Biagini, Paul M O'Neill, Gemma Louise Nixon
A High-throughput screen (HTS) was undertaken against the respiratory chain dehydrogenase component, NADH:menaquinone oxidoreductase (Ndh) of Mycobacterium tuberculosis (Mtb). 11,000 compounds were selected for the HTS based on the known phenothiazine Ndh inhibitors, trifluoperazine and thioridazine. Combined HTS (11,000 compounds) and in-house screening of a limited number of quinolones (50 compounds) identified ~100 hits and four distinct chemotypes, the most promising of which contained the quinolone core...
March 17, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28303399/deinococcus-planocerae-sp-nov-isolated-from-a-marine-flatworm
#9
Huina Lin, Yong Wang, Jiaomei Huang, Qiliang Lai, Ying Xu
A Gram-positive, non-motile and coccoid strain, designated XY-FW106(T), was isolated from a marine flatworm identified to be Planocera sp. The 16S rRNA gene sequence of this pink organism was consistent with membership of the genus Deinococcus, with high sequence similarity to Deinococcus aetherius ST0316(T) (94.7%). The optimum growth temperature range of the strain XY-FW106(T) was found to be 25-30 °C and optimum growth occurs at pH 7.2-7.4 without NaCl. The strain XY-FW106(T) was found to contain unidentified glycolipids, unidentified phosphoglycolipids, unidentified phospholipids and unidentified lipids, which differed from those of closely related species...
March 16, 2017: Antonie Van Leeuwenhoek
https://www.readbyqxmd.com/read/28289918/geodermatophilus-daqingensis-sp-nov-isolated-from-petroleum-contaminated-soil
#10
Yang Wang, Liguo Zhang, Xiaofei Zhang, Jinying Huang, Yu Zhao, Yuanling Zhao, Jianxin Liu, Cui Huang, Jing Wang, Yingying Hu, Guoling Ren, Xiuhong Xu
A novel Gram-positive actinobacterium, designated WT-2-1(T), was isolated from a sample of petroleum-contaminated soil collected in Daqing, Heilongjiang province, China and characterised using a polyphasic taxonomic approach. The optimal growth for strain WT-2-1(T) was found to be at 25-35 °C and at pH 6.0-9.0 and with 0-4% (w/v) NaCl, forming blackish green-coloured colonies. Chemotaxonomic and molecular characteristics of the isolate match those described for members of the genus Geodermatophilus. The peptidoglycan was found to contain meso-diaminopimelic acid; galactose, glucose and xylose were detected as diagnostic sugars...
March 13, 2017: Antonie Van Leeuwenhoek
https://www.readbyqxmd.com/read/28258406/biotransformation-of-menadione-to-its-prenylated-derivative-mk-3-using-recombinant-pichia-pastoris
#11
Zhemin Li, Genhai Zhao, Hui Liu, Yugang Guo, Hefang Wu, Xiaowen Sun, Xihua Wu, Zhiming Zheng
Prenylated quinones, especially menaquinones, have significant physiological activities, but are arduous to synthesize efficiently. Due to the relaxed aromatic substrate specificity and prenylation regiospecificity at the ortho- site of the phenolic hydroxyl group, the aromatic prenyltransferase NovQ from Streptomyces may be useful in menaquinone synthesis from menadione. In this study, NovQ was overexpressed in Pichia pastoris. After fermentation optimization, NovQ production increased by 1617%. Then the different effects of metal ions, detergents and pH on the activity of purified NovQ were investigated to optimize the prenylation reaction...
March 3, 2017: Journal of Industrial Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28258367/enhancing-menaquinone-7-production-by-bacillus-natto-r127-through-the-nutritional-factors-and-surfactant
#12
Xue-Chao Hu, Wei-Ming Liu, Miao-Miao Luo, Lu-Jing Ren, Xiao-Jun Ji, He Huang
Bacillus natto is commonly used in industrial production of menaquinone-7, an important vitamin which plays a crucial role for blood clotting and may contribute to prevention of cardiovascular disease and osteoporosis. This study determined the optimal combination of key nutrients and established an effective use of surfactant in a coupling medium to enhance the yield of extracellular MK-7. MK-7 yield of 31.18 mg/L was achieved under optimal conditions containing 53.6 g/L glycerol, 100 g/L soy peptone, and 10 g/L K2HPO4...
March 3, 2017: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/28243719/hymenobacter-knuensis-sp-nov-isolated%C3%A2-from-river-water
#13
Leonid N Ten, Jae-Jin Lee, Yeon-Hee Lee, Su-Jin Park, Seung-Yeol Lee, Sangkyu Park, Dae Sung Lee, In-Kyu Kang, Myung Kyum Kim, Hee-Young Jung
A Gram-stain-negative, non-motile, non-spore-forming, rod-shaped, aerobic bacterial strain, designated 16F7C-2(T), was isolated from the Han River, South Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain 16F7C-2(T) belonged to the family Cytophagaceae in the phylum Bacteroidetes and was most closely related to Hymenobacter algoricola VUG-A23a(T) (98.3%) and Hymenobacter fastidiosus VUG-A124(T) (97.7%). The G + C content of the genomic DNA of strain 16F7C-2(T) was 63...
April 2017: Current Microbiology
https://www.readbyqxmd.com/read/28230521/micromonospora-terminaliae-sp-nov-an-endophytic-actinobacterium-isolated-from-the-surface-sterilized-stem-of-the-medicinal-plant-terminalia-mucronata
#14
Onuma Kaewkla, Arinthip Thamchaipinet, Christopher Milton Mathew Franco
An endophytic actinobacterium, strain TMS7T, was isolated from the stem of a Thai medicinal plant collected from the grounds of the Phujong-Nayoa National park, Ubon Ratchathani province, Thailand. As a result of a polyphasic taxonomy study, this strain was identified as a member of the genus Micromonospora. This strain was a Gram-stain-positive, aerobic actinobacterium with well-developed substrate mycelium with hyphae forming a single microspore was non-motile. Stran TMS7T was identified according to its 16S rRNA gene sequence as a new member of the genus Micromonospora...
February 24, 2017: International Journal of Systematic and Evolutionary Microbiology
https://www.readbyqxmd.com/read/28225275/synthesis-of-novel-synthetic-vitamin-k-analogues-prepared-by-introduction-of-a-heteroatom-and-a-phenyl-group-that-induce-highly-selective-neuronal-differentiation-of-neuronal-progenitor-cells
#15
Kimito Kimura, Yoshihisa Hirota, Shigefumi Kuwahara, Atsuko Takeuchi, Chisato Tode, Akimori Wada, Naomi Osakabe, Yoshitomo Suhara
We synthesized novel vitamin K2 analogues that incorporated a heteroatom and an aromatic ring in the side chain and evaluated their effect on the selective differentiation of neuronal progenitor cells into neurons in vitro. The results showed that a menaquinone-2 analogue bearing a p-fluoroaniline had the most potent activity, which was more than twice as great as the control. In addition, the neuronal selectivity was more than 3 times greater than the control.
March 3, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28221135/impaired-respiration-elicits-srrab-dependent-programmed-cell-lysis-and-biofilm-formation-in-staphylococcus-aureus
#16
Ameya A Mashruwala, Adriana van de Guchte, Jeffrey M Boyd
Biofilms are communities of microorganisms attached to a surface or each other. Biofilm-associated cells are the etiologic agents of recurrent Staphylococcus aureus infections. Infected human tissues are hypoxic or anoxic. S. aureus increases biofilm formation in response to hypoxia, but how this occurs is unknown. In the current study we report that oxygen influences biofilm formation in its capacity as a terminal electron acceptor for cellular respiration. Genetic, physiological, or chemical inhibition of respiratory processes elicited increased biofilm formation...
February 21, 2017: ELife
https://www.readbyqxmd.com/read/28211312/olivibacter-composti-sp-nov-isolated-from-compost-collected-at-a-greenhouse
#17
Shih-Yao Lin, Asif Hameed, Kai-Yeh Chiu, You-Cheng Liu, Yi-Han Hsu, Wei-An Lai, Chiu-Chung Young
A polyphasic approach was used to characterize a presumably novel bacterium, designated strain CC-KYC063T, isolated from a compost sample collected at a greenhouse facility within Taiwan. Strain CC-KYC063T was Gram-stain-negative and aerobic, able to grow at 15-37 °C (optimal 30 °C), at pH 7.0-9.0 (optimal pH 7.0) and with 0-2 % (w/v) NaCl. The 16S rRNA gene sequence of strain CC-KYC063T showed highest similarity to Olivibacter ginsengisoli Gsoil 060T (96.2 %) and Olivibacter terrae Jip13T (95.5 %)...
January 2017: International Journal of Systematic and Evolutionary Microbiology
https://www.readbyqxmd.com/read/28197940/the-change-of-the-state-of-cell-membrane-can-enhance-the-synthesis-of-menaquinone-in-escherichia-coli
#18
Yan Liu, Xiu-Min Ding, Zheng-Lian Xue, Liu-Xiu Hu, Ning-Juan Zhang, Zhou Wang, Jian-Wei Yang, Qian Cheng, Ming-Hong Chen, Zhuang-Zhuang Zhang, Zhi-Ming Zheng
Menaquinone (MK) was an attractive membrane-bound intracellular chemical. To enhance its production, we tried to find the relationship between its synthesis and the state of cell membrane in producing strain. Due to non-ionic surfactant-polyoxyethylene oleyl ether (POE) and plant oil-cedar wood oil (CWO) can typically increase extracellular secretion and intracellular synthesis of MK respectively, the effect of these two substances on cell morphology, physical properties of cell membrane was investigated. Finally, two engineering strains were constructed to verify whether the state of cell membrane can enhance MK synthesis...
March 2017: World Journal of Microbiology & Biotechnology
https://www.readbyqxmd.com/read/28196957/a-novel-small-molecule-inhibitor-of-the-mycobacterium-tuberculosis-demethylmenaquinone-methyltransferase-meng-is-bactericidal-to-both-growing-and-nutritionally-deprived-persister-cells
#19
Paridhi Sukheja, Pradeep Kumar, Nisha Mittal, Shao-Gang Li, Eric Singleton, Riccardo Russo, Alexander L Perryman, Riju Shrestha, Divya Awasthi, Seema Husain, Patricia Soteropoulos, Roman Brukh, Nancy Connell, Joel S Freundlich, David Alland
Active tuberculosis (TB) and latent Mycobacterium tuberculosis infection both require lengthy treatments to achieve durable cures. This problem has partly been attributable to the existence of nonreplicating M. tuberculosis "persisters" that are difficult to kill using conventional anti-TB treatments. Compounds that target the respiratory pathway have the potential to kill both replicating and persistent M. tuberculosis and shorten TB treatment, as this pathway is essential in both metabolic states. We developed a novel respiratory pathway-specific whole-cell screen to identify new respiration inhibitors...
February 14, 2017: MBio
https://www.readbyqxmd.com/read/28195212/loss-of-oxyr-reduces-efficacy-of-oxygen-respiration-in-shewanella-oneidensis
#20
Fen Wan, Miaomiao Shi, Haichun Gao
In many bacteria, OxyR is the major regulator controlling cellular response to H2O2. A common phenotype resulting from OxyR loss is reduced growth rate, but the underlying mechanism is unknown. We demonstrated in Shewanella oneidensis, an important research model for applied and environmental microbes, that the defect is primarily due to an electron shortage to major terminal oxidase cytochrome cbb3. The loss of OxyR leads to enhanced production of electron carriers that compete for electrons against cytochrome cbb3, cytochrome bd in particular...
February 14, 2017: Scientific Reports
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